Metamath Proof Explorer


Theorem ordtype2

Description: For any set-like well-ordered class, if the order isomorphism exists (is a set), then it maps some ordinal onto A isomorphically. Otherwise, F is a proper class, which implies that either ran F C_ A is a proper class or dom F = On . This weak version of ordtype does not require the Axiom of Replacement. (Contributed by Mario Carneiro, 25-Jun-2015)

Ref Expression
Hypothesis oicl.1 F=OrdIsoRA
Assertion ordtype2 RWeARSeAFVFIsomE,RdomFA

Proof

Step Hyp Ref Expression
1 oicl.1 F=OrdIsoRA
2 eqid recshVιvwA|jranhjRw|uwA|jranhjRw¬uRv=recshVιvwA|jranhjRw|uwA|jranhjRw¬uRv
3 eqid wA|jranhjRw=wA|jranhjRw
4 eqid hVιvwA|jranhjRw|uwA|jranhjRw¬uRv=hVιvwA|jranhjRw|uwA|jranhjRw¬uRv
5 2 3 4 ordtypecbv recsfVιsyA|iranfiRy|ryA|iranfiRy¬rRs=recshVιvwA|jranhjRw|uwA|jranhjRw¬uRv
6 eqid xOn|tAzrecsfVιsyA|iranfiRy|ryA|iranfiRy¬rRsxzRt=xOn|tAzrecsfVιsyA|iranfiRy|ryA|iranfiRy¬rRsxzRt
7 simp1 RWeARSeAFVRWeA
8 simp2 RWeARSeAFVRSeA
9 simp3 RWeARSeAFVFV
10 5 3 4 6 1 7 8 9 ordtypelem9 RWeARSeAFVFIsomE,RdomFA